Window covering motorized lift and control operating system

ABSTRACT

A window covering includes a movable window covering material, cords for moving the window covering material, and a motorized lift assembly. The motorized lift assembly includes a motor assembly including a motor, a gear train driven by the motor for adjusting positions of the cords, and an operating and control device mounted to a portion of the window covering for operating the motor in response to user input.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a national stage entry of InternationalPatent Application Number PCT/US2014/028234, filed Mar. 14, 2014, whichclaims the benefits of, and priority to U.S. Provisional ApplicationSer. No. 61/792,226, filed Mar. 15, 2013, the contents of which arehereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to window coverings, and, morespecifically, to motorized window coverings and the operating systemsprovided therefor.

BACKGROUND OF THE INVENTION

Motorized operating systems have been provided for window coverings ofvarious types. Often the systems have been expensive and somewhatdifficult to install, prepare for use and operate. Known systems havebeen noisy and large in physical size. Many are relatively inflexible,being factory programmed for specific operations and performance, whileenabling little, if any user input, adjustment or alteration to thefactory installed programming. As a result, motorized operating systemshave been found most often on shades for extremely large windows,windows that are difficult to access for manual operation of a shade orfor windows in commercial settings. Motorized operating systems have notachieved wide acceptance or use in residential use situations.

SUMMARY OF THE INVENTION

The window covering motorized lift and control system disclosed hereinprovides a low-cost, yet efficient and reliable motorized operatingsystem for window coverings of many different types, styles and sizes.Plastic gears are used for the cost and noise benefits gained therewith. For increased strength, helical plastic gears and gear traincomponents are used, and the structural arrangements and configurationsof the components overcome thrust loading and other forces that havemade the use of small plastic helical gears unsuccessful in the past. Ahigh speed motor is used with multiple planetary gear stages for speedreduction. The drive assembly and drive shaft are arranged side-by-sidefor a compact assembly. A magnetic encoder also provides magneticbraking A variety of sensors can be incorporated into the bottom rail ofthe window covering and/or into a hand held user input device to improveperformance and reliability.

Other features and advantages of the invention will become apparent tothose skilled in the art upon review of the following detaileddescription, claims and drawings in which like numerals are used todesignate like features.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective illustration of a window covering on a window;

FIG. 2 is a top view into the window covering head rail;

FIG. 3 is a perspective view of the motorized lift assembly in thewindow covering;

FIG. 4 is an exploded view of the motorized lift assembly;

FIG. 5 is a perspective view of the motor and drive assembly in the liftassembly;

FIG. 6 is an elevational view of the motor and drive assembly;

FIG. 7 is an elevational view of the motor and drive assembly from adifferent angle;

FIG. 8 is a cross-sectional view of the motor and drive assembly, thecross-section taken on line 8-8 of FIG. 7;

FIG. 9 is an exploded view of the motor and drive assembly;

FIG. 10 is an exploded view of the motor and drive assembly takengenerally from an opposite perspective to that shown in FIG. 9;

FIG. 11 is a perspective view of the motor assembly;

FIG. 12 is an elevational view of the motor assembly;

FIG. 13 is an end view of the motor assembly;

FIG. 14 is an exploded view of the motor assembly;

FIG. 15 is another elevational view of the motor assembly;

FIG. 16 is a perspective view of a ring magnet in the motor assembly;

FIG. 17 is a perspective view of a magnet insert in the motor assembly;

FIG. 18 is a perspective view of an encoder isolator in the motorassembly;

FIG. 19 is another perspective view of the encoder isolator, showing theside opposite the side shown in FIG. 18;

FIG. 20 is a perspective view of a ring gear in the gear train of themotor and drive assembly;

FIG. 21 is an end view of the ring gear;

FIG. 22 is a perspective view of a planet gear in the gear train;

FIG. 23 is an end view of the planet gear shown in FIG. 22;

FIG. 24 is an elevational view of the planet gear shown in FIGS. 22 and23;

FIG. 25 is a perspective view of a sun gear in the gear train;

FIG. 26 is another perspective view of the sun gear generally showingthe side opposite the side shown in FIG. 25;

FIG. 27 is an elevational view of the sun gear shown in FIGS. 25 and 26;

FIG. 28 is a perspective view of a planet gear carrier in the geartrain;

FIG. 29 is a perspective view of the planet gear carrier from an angledifferent than that of FIG. 28;

FIG. 30 is an elevational view of the planet gear carrier shown in FIGS.28 and 29;

FIG. 31 is a perspective view of another type of planet gear carrier inthe gear train;

FIG. 32 is an end view of the planet gear carrier shown in FIG. 31;

FIG. 33 is an elevational view of the planet gear carrier shown in FIGS.31 and 32;

FIG. 34 is a perspective view of an output shaft in the gear train;

FIG. 35 is another perspective view of the output shaft shown in FIG.34, with the output shaft being shown from a different angle than thatof FIG. 34;

FIG. 36 is a plan view of the output shaft shown in FIGS. 34 & 35;

FIG. 37 an end view of the output shaft shown in FIGS. 34-36;

FIG. 38 is a cross-sectional view of the gear train assembly;

FIG. 39 is a perspective view of an output assembly in the motor anddrive assembly, the output assembly including the planet gear carriershown in FIGS. 31-33 and the output shaft shown in FIGS. 34-37;

FIG. 40 is another perspective view of the output assembly shown in FIG.39, but showing the output assembly from a different angle than thatfrom which it is shown in FIG. 39;

FIG. 41 is a fragmentary perspective view of another window covering ona window;

FIG. 42 is a fragmentary perspective view of still another windowcovering on a FIG. 43 is a fragmentary perspective view of a furtherwindow covering on a window;

FIG. 43 is a fragmentary perspective view of a further window coveringon a window; and

FIG. 44 is a fragmentary perspective view of a still further windowcovering on a window.

Before the embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangements of the components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments and of being practiced orbeing carried out in various ways. Also, it is understood that thephraseology and terminology used herein are for the purpose ofdescription and should not be regarded as limiting. The use herein of“including”, “comprising” and variations thereof is meant to encompassthe items listed thereafter and equivalents thereof, as well asadditional items and equivalents thereof.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings more specifically, and to FIG. 1 inparticular, a window covering 100 is shown on an architectural opening190, such as a window. Window covering 100 includes a head rail 102, abottom rail 104 and window covering material 106, such as a fabricmaterial as shown in the exemplary embodiment, extending between headrail 102 and bottom rail 104. It should be understood that the mechanismand system to be described hereinafter can be used on window coveringsof various types, and the specific type shown is merely one example. Forexample, the mechanism and system disclosed herein can be adapted foruse on various types of horizontal blinds and shades to move the blindor shade vertically, as well as on vertical window coverings such asdrapes to move the window covering horizontally.

As shown in FIG. 2, window covering 100 includes lift cords 108 forraising and lowering window covering material 106, two such lift cords108 being shown in the drawings. For larger window coverings, three ormore lift cords might be used. As known to those skilled in the art, arotatable lift cord take-up shaft or mandrel 110 is provided about whichthe lift cords 108 are wound and unwound for raising and lowering windowcovering material 106. Each of the lift cords 108 is connected at oneend to bottom rail 104 and at the opposite end to lift cord take-upshaft 110. Lift cords 108 extend through window covering material 106between head rail 102 and bottom rail 104. Again, various types ofrotatable structures can be used for winding and unwinding the liftcords as bottom rail 104 is raised or lowered to expose or coverportions of the window there behind.

Window covering 100 is a motor operated window covering having amotorized lift assembly 120 provided for rotating take-up shaft 110 whenlifting and lowering bottom rail 104. Motorized lift assembly 120 fitssnugly and securely into head rail 102. Referring now to FIGS. 3 & 4,motorized lift assembly 120 includes an upper housing 122, a lowerhousing 124 and end isolators 126, 128. Upper and lower housings 122,124 can be of various materials including plastics and metals, such as,for example, aluminum. Other materials, including other metals also aresuitable for upper housing 12 and lower housing 124. End isolators 126,128 are of resilient materials for damping vibrations, muffling soundsand effectively sealing the ends of the assembled upper and lowerhousings 122, 124 for sound management purposes. End isolators 126, 128also facilitate the secure, yet resilient mounting of motorized liftassembly 120 within head rail 102, to further assist in the managementand mitigation of sound and vibrations. End isolators 126, 128 fitsecurely in head rail 102 and provide a resilient suspension formotorized lift assembly 120 within headrail 102, thereby isolatingmotorized lift assembly 120 from direct contact with head rail 102, andminimizing transfer to head rail 102 of sound and vibration generated bymotorized lift assembly 120.

Within the assembled upper housing 122 and lower housing 124, motorizedlift assembly 120 includes a motor and drive assembly 130 having anoutput driving gear 132 that is drivingly engaged with a driven gear 134for rotating a driveshaft 136. Driveshaft 136 is operatively anddrivingly connected to lift cord take-up shaft 110, so that operation ofmotor and drive assembly 130 rotates drive shaft 136 which in turnrotates lift cord take-up shaft 110.

A power source 140 (FIG. 2) is provided for supplying electrical powerto operate motorized lift assembly 120. Those skilled in the art willreadily understand and recognize that power source 140 can be aconnection to a source of alternating current, such as the electricalsystem of the building in which the window covering is installed. In theexemplary embodiment shown, power source 140 is a direct current powersource including a plurality of batteries 142 contained in a batterycompartment 144. An electrical lead 146 is provided from the batteries142 in battery compartment 144 to motor and drive assembly 130.Batteries of various types can be used, including common single usebatteries and rechargeable batteries. A solar recharging system can beincorporated into the structure for continuously recharging rechargeablebatteries, and photovoltaic pads for the charging system can be providedon surfaces of window covering 100, such as surfaces of head rail 102,bottom rail 104 and/or window covering material 106. Alternatively oradditional, photovoltaic cells can be provided in other locations andelectrically connected to rechargeable batteries in power source 140.Further, battery compartment 144 can be located and contained in otherlocations and in other ways. For example, in some installations thebattery compartment can be relatively independent from window covering100, connected thereto only by electrical lead 146, and concealed withina window frame, or located behind and generally concealed by the headrail and stacked window covering material even when the window is fullyexposed and the covering material raised as high as possible. Stillfurther, a false or extended front of the head rail can be used toconceal the power source, and hinged in such a manner as to tiltdownwardly, exposing the battery compartment for easy access to thebatteries for replacement. As yet another alternative, a battery andbattery compartment may be contained in the bottom rail of a windowcovering, thereby allowing easy access for battery replacement.

An operating and control device 150 (FIG. 1) is provided for operatingmotorized lift assembly 120. Operating and control device 150 includes ahandheld remote control user input device 152 and a remote controlmounting device 154 for receiving and holding the handheld remotecontrol user input device 152. Mounting device 154 can be installed ator near window covering 100, such as on a window frame, adjacent wall,or the like. Further, mounting device 154 can be placed at any otherlocation of convenience, such as another wall, for example. Severalmounting devices can be used, each placed at a different desirablelocation for conveniently holding remote control user input device 152.Mounting device 154 is merely a holder for retaining remote control userinput device 152 for easy location and access. Remote control user inputdevice 152 can be removed from mounting device 154 and carried on aperson, placed on a surface or otherwise located and used. Mountingdevice 154 is not required for the operation of remote control userinput device 152 and is instead provided for user convenience. However,remote control user input device 152 can be accessed and operated whileretained in mounting device 154. It is not required to remove remotecontrol user input device 152 from mounting device 154 for the operationof remote control user input device 152. As still another alternative,mounting device 154 can be connected electrically to the building ACpower system, to an independent power system, or to a solarcharging/supply system, and electrically connected to user input device152 for charging batteries in device 152 when device 152 is placed inmounting device 154.

Referring now again to FIGS. 3 and 4, motorized lift assembly 120further includes a PCB shroud 160 associated with upper housing 122 andlower housing 124 for retaining a printed circuit board 162 for theoperation and control of motorized lift assembly 120.

As shown in FIG. 4, motor and drive assembly 130 and driveshaft 136 arepositioned adjacent one another in the assembly within upper housing 122and lower housing 124. That is, drive assembly 130 and driveshaft 136are positioned generally side-by-side and not end-to-end. Accordingly,the overall footprint required for motorized lift assembly 120 is smallin length, unlike known structures in which the components of motor anddrive assemblies of motorized lift assemblies are positioned axiallyend-to-end with one another. The motorized lift assembly disclosedherein can be used on narrow width window coverings having minimal spacenot required for the lift cords and lift cord take-up shaft. The throughshaft design in which a gear is provided at the driven end of driveshaft136 also enables the use of standard spring motors and the like asauxiliary or “helper” motors. Driveshaft 136 can project outwardlybeyond the driven gear 134 engaged thereon in the bypass design havingmotor and drive assembly 130 generally adjacent and parallel todriveshaft 136. An exposed portion of the driveshaft projecting beyondthe driven gear 134 can receive a spring motor of design known to thoseskilled in the window covering art. Accordingly, a spring motor assistcan be provided along with the operation of motorized lift assembly 120.Spring motor assist can be particularly advantageous when provided forlarge window coverings and/or for window coverings of particularly heavyweight.

Motor and drive assembly 130 includes a motor assembly 200 and a geartrain 300. Motor assembly 200 and gear train 300 are connected to oneanother not only by the driving relationships of the motor assembly 200and gear train 300, but also physically by fasteners and otherconnections for the management and control of load forces created duringoperation. Accordingly, motor assembly 200 defines flat surfaces 170,172 on opposite sides thereof, and gear train 300 provides projections174, 176 overlying and engaging flat surfaces 170, 172 in the assembledmotor and drive assembly 130. Fasteners 178 can be used for physicallyattaching projections 174, 176 to flat surfaces 170, 172. As a result,rotational and axial forces tending to move motor assembly 200 and geartrain 300 relative to one another are resisted and inhibited by theprojections 174, 176 engaging the flat surfaces 170, 172 and thephysical attachment of motor assembly 200 and gear train 300 by way offasteners 178.

Motor assembly 200 includes a motor 202 connected by a ribbon cable 204to the provided systems for power and control, including in theexemplary embodiment shown power source 140 and printed circuit board162. A motor shaft 206 extends through motor 202 for drive connection onone end thereof to gear train 300, and control function at the oppositeend thereof. On the control end of motor 202, an encoder isolator 208includes a sidewall 210 (FIGS. 18 and 19) surrounding and encapsulatingportions of the outer end edge of motor 202. Encoder isolator 208electrically separates motor 202 from an encoder board 212. Encoderisolator 208 is resilient material, such as silicone, and also serves toresiliently mount motor 202 in upper housing 122 and lower housing 124.Sidewall 210 is configured to engage a shaped cavity provided in theassembled upper housing 122 and lower housing 124. To that end, sidewall210 is shaped so as to engage the inner surface of the assembled upperhousing 122 and lower housing 124 in selected multiple locations lessthan the full extent of its circumference. The relatively softerdurometer in a multi-point contact with the housing isolates the motorfrom transmitting mechanical vibrations and sound to the housing whileserving also as electrical and mechanical insulation between the encoderboard and the motor. Accordingly, encoder isolator 208 establishes asecond level of isolation to that provided by end isolators 126, 128 toinhibit the transfer of sound and vibration.

Motor 202 is a low-voltage, high-speed window shade motor. Motor 202operates at much higher speed (rpm) than window shade motors previouslyknown to be used, and provides improved power to size performance.Whereas it has been known in the past to use motors operating in therange of 6,000 to 12,000 rpm, motor 202 within the system disclosedherein operates in a range of about 15,000 rpm to about 20,000 rpm.Increased torque is achieved through increased speed rather than bymotor size-up. Slower motors used previously operated at 50-60%efficiency, whereas the higher speed motors proposed herein can beoperate readily at about 60-70% efficiency, thereby achieving operatingadvantages. A further benefit relating to operation and control isachieved from the use of a high speed motor 202 in the motorized liftassembly. An encoder reading on the higher speed output will “read” morefrequently in a given time period than an encoder operating on a lowerspeed motor output. If each is geared to the same final output speed foroperating the window shade, the operating system with the higher motorspeed can be controlled more precisely than the operating system with alower motor speed.

Encoder board 212 is affixed to the end of motor 202 by first and secondscrews 214, 216 generally positioned on opposite sides thereof. Acentral opening 218 in encoder board 212 accommodates the projecting endof motor shaft 206. Hall sensors 220, 222 are provided on encoder board212. A ring magnet 224 having an axial opening 226 is secured to the endof motor shaft 206 by a magnet insert 228 which establishes acompression fit of the magnet on the motor shaft. Accordingly, magnetinsert 228 includes a head 230 and cylinder 232 together defining anaxial opening 234 extending through magnet insert 228. A diameter ofaxial opening 234 is selected to engage motor shaft 206 by aninterference fit. The outer diameter of cylinder 232 is selected toengage axial opening 226 of ring magnet 224 also by interference fit.Accordingly, by establishing interference fit relationships with bothmotor shaft 206 and ring magnet 224 magnet insert 228 secures ringmagnet 224 on the motor shaft 206 so that the ring magnet rotatestogether with motor shaft 206. Hall sensors 220, 222 detect and relayinformation about the magnetic field created by magnet 224 as thatmagnetic field changes while the magnet rotates together with motorshaft 206. Accordingly, the information gathered can be used todetermine rotations of motor 202 and therefore the distance traveled bywindow covering material 106 as the motor shaft rotates during liftingor lowering of the window covering material.

Screws 214, 216 are metal and thereby influence the rotation of ringmagnet 224 at low speeds or when stopped. As the rotation of motor shaft206 slows, ring magnet 224 seeks a balanced position relative to thefixed positions of metallic screws 214, 216. The magnetic field issufficiently strong to act as a brake against the rotation of motorshaft 206 from a stopped condition. Accordingly ring magnet 224 servesthe dual purposes of acting as a component of an encoder for operationand control during operation and as a component of a brake againstunintended rotation or free-wheeling when the operation of motor 202 isslowed or stopped.

At the driving end of motor 202, motor assembly 200 includes a ring gearmount 236 having a body portion 238 with axially projecting wings 240,242 on opposite sides thereof. Wings 240, 242 slide against and engageflat surfaces 170, 172 during assembly. As assembled, wings 240, 242associated with flat surfaces 170, 172 inhibit relative rotation betweenring gear mount 236 and motor 202. Ring gear mount 236 is connected tomotor 202 by first and second screws 244, 246 extending into an end faceof motor 202. Accordingly, ring gear mount 236 is solidly connected tomotor 202.

A sun gear 250 is drivingly mounted on the projecting end of motor shaft206. Sun gear 250 is the driving connection between motor assembly 200and gear train 300. Sun gear 250 includes helical gear teeth 252 and abase 254. Base 254 is slightly larger in diameter than the maximumdiameter defined by the tips of helical gear teeth 252. Helical gearteeth 252 meet a distal end surface 256 of base 254 and extend axiallyoutward therefrom. A shoulder 258 of base 254 extends laterally ofdistal end surface 256, and thus laterally beyond the tips of helicalgear teeth 252 where the gear teeth meet distal end surface 256.Shoulder 258 is disposed at a slight chamfer or slope rearward relativeto distal end surface 256, and therefore away from gear teeth 252.

Gear train 300 includes a plurality of epicyclic gears, and in theexemplary embodiment shown includes primary, secondary and tertiaryspeed reducing planetary gear stages 302, 304, 306, respectively,contained within a single elongated fixed annular or ring gear 308.Planetary gear stages 302, 304, 306 are helical in design. That is, eachgear therein includes helical gear teeth, as does ring gear 308.Further, the individual gears in gear train 300 to be describedsubsequently are made of plastic. When made of molded plastic,substantial cost savings are achieved, thereby making a motorized shadeof the present description more practical for smaller and lower costwindow coverings. Since the use of plastic gears can createdisadvantages, such as reduced strength compared to metal gears, helicalgears have been selected for the strength and noise advantages theyprovide. It is known that small, lightweight plastic helical gears cancause other problems as a result of deflection from thrust loads in thebasic design that must be accommodated to maintain proper gear meshing,balancing and operating efficiency. For this reason, planetary gearshave not been used commonly in small lightweight plastic gear trainsbecause it has been difficult to accommodate the various thrust forcesgenerated by planetary gears. The present design addresses thoseproblems.

Primary planetary gear stage 302 and secondary planetary gear stage 304are similarly constructed and include interchangeable planet gearcarriers 310, 312, respectively. Each planet gear carrier 310, 312includes three similarly constructed planet gears, including planetgears 314, 316, 318 on primary planetary gear stage planet gear carrier310, and planet gears 320, 322, 324 on secondary planetary gear stageplanet gear carrier 312.

Ring gear 308 is a generally cylindrical body having an open end 326 atthe end thereof defining the aforedescribed projections 174, 176.Projections 174, 176 each define a hole 328, 330, respectively, forreceiving a fastener 178 which extends therethrough and is received inring gear mount 236. Internally, ring gear 308 defines helical gearteeth 332. At the end opposite projections 174, 176 a substantiallyclosed end wall 334 is provided, defining a centrally positioned hole336.

Planet gear carrier 310 includes a plate 340 having legs 342, 344, 346projecting outwardly from one surface thereof and an integral sun gear348 projecting from the opposite surface thereof. Each leg 342, 344, 346has a laterally projecting foot 350, 352, 354, respectively, at thedistal end thereof. An inner surface 356, 358, 360 of, respectively,each leg 342, 344, 346 generally opposite from the laterally projectingfoot 350, 352, 354 of the leg is inwardly sloped, thus defining athinner region for each leg 342, 344, 346 at the distal end of the leg,which grows thicker in the proximal direction for a portion of thelength of each leg 342, 344, 346. A collar 362, 364, 366 is provided atthe base of each leg 342, 344, 346 and partly surrounds an inner portionof the leg with which it is associated.

Sun gear 348 is centrally positioned on plate 340 and defines helicalgear teeth 368. At the proximal end of sun gear 348, plate 340 defines achamfered or sloping surface 370 radially outward of the proximal endsof gear teeth 368, the sloping surface 370 sloping away from helicalgear teeth 368.

Planet gear carrier 312 is similarly constructed to planet gear carrier310, and is interchangeable therewith. Planet gear carrier 312 includesa plate 380 having legs 382, 384, 386 projecting outwardly from onesurface thereof, and an integral sun gear 388 projecting from theopposite surface thereof. Each leg 382, 384, 386 has a laterallyprojecting foot at the distal end thereof, and an inner surfacegenerally opposite from the laterally projecting foot that is inwardlysloped, thus defining a thinner region for each leg 382, 384, 386 at thedistal end of the leg, which grows thicker in the proximal direction fora portion of the length of each leg 382, 384, 386; all as describedabove with respect to the corresponding features of planet gear carrier310. A collar is provided at the base of each leg 382, 384, 386 andpartly surrounds an inner portion of the leg with which it isassociated, also as described above with respect to planet gear carrier310.

Sun gear 388 is centrally positioned on plate 380 and defines helicalgear teeth 408. At the proximal end of sun gear 388, the plate 380defines a chamfered or sloping surface 410 radially outward of theproximal ends of gear teeth 408, the sloping surface 410 sloping awayfrom helical gear teeth 408.

Tertiary planetary gear stage 306 includes a planet gear carrier 420 andfour similarly constructed planet gears 422, 424, 426, 428. Planet gearcarrier 420 includes a plate 430 having legs 432, 434, 436, 438projecting outwardly from one surface thereof and an integral boss 440projecting from the opposite surface thereof. Each leg 432, 434, 436,438 has a laterally projecting foot 442, 444, 446, 448, respectively, atthe distal end thereof. An inner surface 450, 452, 454, 456 of,respectively, each leg 432, 434, 436, 438 generally opposite from thelaterally projecting foot 442, 444, 446, 446 is inwardly sloped, thusdefining a thinner region for each leg 432, 434, 436, 438 at the distalend of the leg which grows thicker in the proximal direction for aportion of the length of each leg 432, 434, 436, 438. A collar 458, 460,462, 464 is provided at the base of each leg 432, 434, 436, 438 andpartly surrounds an inner portion of the leg with which it isassociated.

Boss 440 is centrally positioned on plate 430 and defines anoncontinuous s collar 466 at the end thereof, noncontinuous collar 466having a noncontinuous circumferential snap ring channel 468. Boss 440further defines a shaped axial hole 470 extending therethrough. Boss 440receives an output shaft 472 drivingly engaged with tertiary planet gearcarrier 420 via shaped hole 470 in boss 440 engaging a complementarilyshaped inner segment 474 of output shaft 472. Output shaft 472 furtherdefines a boss 476, generally rectangular in shape with rounded endsdefining snap ring channel segments 478, 480. Boss 476 fits within theopen areas of noncontinuous collar 466 and snap ring channel segments478, 480 complete a circumferential snap ring channel with thenoncontinuous snap ring channel 468. At the inner end of shaped innersegment 474, a pedestal 482 includes a snap connecting head 484.Pedestal 482 and snap connecting head 484 project into secondary stageplanet gear carrier 312 and engage the carrier axially so that thesecondary and tertiary stages are axially tied together. Thisinterconnection between the secondary and tertiary stages further helpsmanage thrust loads developed in the gear train.

Output shaft 472 extends outwardly of ring gear 308, extending throughhole 336 in end wall 334. Outwardly of ring gear 308, output shaft 472defines a drive configuration 486 for drivingly connecting to outputdriving gear 132. A drive isolator 488 is interposed between driveconfiguration 486 and output driving gear 132 mounted thereon. Driveisolator 488 is a shaped body of resilient material to inhibit theconduction of vibrations and sound from output shaft 472 to outputdriving gear 132, thus providing yet another level of isolation forsound and vibration control.

An elongated motor and drive assembly isolator 490 is connected to theend of ring gear 308 by a plurality of screws 492. Motor and driveassembly isolator 490 is of resilient material and positions and retainsmotor and drive assembly 130 within a shaped cavity provided by theassembled upper housing 122 and lower housing 124. Motor and driveassembly isolator 490 provides resilient yet firm positioning of themotor and drive assembly to help maintain proper alignment andpositioning while damping the transmission of vibration and sound.

Each of the planet gears 314, 316, 318, 320, 322, 324, 422, 424, 426,428 is similarly constructed to the other planet gears. Therefore, onlyone exemplary planet gear 314 will be described. It should be recognizedthat all of the planet gears 314, 316, 318, 320, 322, 324, 422, 424,426, 428 are the same, and thus are interchangeable with one anotherwithin gear train 300. Planet gear 314 defines helical gear teeth 494along its outer surface and running surfaces 496, 498 at opposite endsof planet gear 314.

Each of the planet gears 314, 316, 318, 320, 322, 324, 422, 424, 426,428 will fit on any of the legs 342, 344, 346, 382, 384, 386, 432, 434,436, 438 of the planet gear carriers 310, 312, 420 between the foot atthe distal end of the leg and the collar at the proximal end of the leg.Once installed, the planet gears fit on the legs without significantplay axially or radially, running against the feet at the outer ends ofthe planet gears and the collars at the inner ends of the planet gears.The inwardly sloped inner surfaces of the legs allow a planet gear to betilted to slide over the foot of the leg without significantinterference or resistance and without a need to deflect features of thecarriers and gears. Since each planet gear is mounted on a leg in asimilar manner, only the mounting of the exemplary planet gear 314 willbe described relative to its mounting on leg 342, with the understandingthat each of the planet gears 314, 316, 318, 320, 322, 324, 422, 424,426, 428 is mounted in a similar fashion, one planet gear on each leg342, 344, 346, 382, 384, 386, 432, 434, 436, 438.

Planet gear 314 is tilted outwardly generally in line with foot 350 andis slid onto the distal end of leg 342. Sloping inner surface 356 allowsthe tilted planet gear to slide along the length of the leg, with theplanet gear straightening and aligning with the axis of leg 342 as theplanet gear approaches collar 362. When the planet gear is fully mountedon the leg, foot 350 confronts one of the end running surfaces 496, 498,and collar 362 confronts the other of the end running surfaces 496, 498.It should be noted that foot 350 and all of the other feet previouslydescribed is relatively narrow and provides little running resistanceagainst the confronting surface of the planet gear. Similarly, collar362 only partly encircles leg 342 and provides little running resistanceagainst the other of the confronting surfaces of the planet gear.

In the assembled form of gear train 300, the primary, secondary andtertiary planetary gear stages are held in ring gear 308, with theplanet gears of the planetary gear stages drivingly engaged with helicalgear teeth 332 of ring gear 308. In the assembled configuration, theplanet gears are not enabled to tilt outwardly due to the closelyfitting engagement with ring gear 308. Accordingly, each planet gearremains axially aligned with the leg on which it is installed andoperates smoothly both rotating on the leg and revolving within ringgear 308.

The primary, secondary and tertiary planetary gear stages are snugly fitone against the other axially within ring gear 308. Sun gear 250 engagesplanet gears 314, 316, 318 on planet gear carrier 310. Sun gear 348 ofplanet gear carrier 310 engages planet gears 320, 322, 324 on planetgear carrier 312. Sun gear 388 of planet gear carrier 312 engages thefour planet gears 422, 424, 426, 428 operating on planet gear carrier314. Chamfered or sloping shoulder 258 and chamfered or sloping surfaces370, 410 engage the respective planet gears operating there against. Thehelical design of the planetary threads creates an axial thrust load atthe motor. The chamfered sloping shoulder end surfaces allow nonplanarcontact close to the operating pitch were less sliding occurs and closerto the center to provide the least friction when load is applied.Accordingly, less resistance and less wear are experienced.

To prevent shade drift (unintended lowering over time); in lower speedmotor operating systems it has been necessary to increase the naturalrotational resistance present in the motor. Additional expensive magnetshave been used to achieve the increased resistance. In the operatingsystem disclosed herein, using high-speed motor 202 and gear train 300to provide the speed reduction necessary to step the speed down providessufficient inherent rotation resistance to prevent drift in averageshades, without the need for add-on magnets.

The controls, motor and gear train are made in a sufficiently small formfactor to be useable in a variety of different types of windowcoverings, with changes only to final gearing necessary for a particularproduct. High speed motors as described herein tend to have higherfrequency noise, which can be mitigated somewhat more easily. Thehousing containing the motor and other components can be designed as asound chamber to suppress noise. The various rubberized mounts shown anddescribed herein can further aid noise suppression, as well asfacilitating torque control.

A specific method of system feedback may be implemented into theoperation of motor 202, allowing audible verification by a beep or othertone to indicate that an event or command has been implemented properly.The audible verification tone can be used in place of methods thatexpose a visible feedback cue (e.g. a jog of window covering material106), to avoid moving the window covering itself to provide feedback; oran audible verification tone can be used in conjunction with a visiblefeedback cue. This system can use the de motor itself to produce a soundassociated with a specific feedback message. The feedback tone can begenerated by applying a current to both poles of the motorsimultaneously at a specified frequency. Oscillating between conditionsof the motor drive, counterclockwise to clockwise, and/or braking at aspecific rate can generate sounds in the human audible range. This isessentially vibrating the coils inside the motor without actually movingthe window covering a measurable distance. The tone of the sound emittedfrom rapid alterations of motor operation is a function related to thefrequency of the in-phase modulated motor pole signals. Multiple tonesmay be generated to provide multiple feedback or status messages toindicate to the user that a commanded operation has been completed, orto alert the user to a specific condition in the system, such as, forexample, a low battery condition.

A control system for operating the window covering is designed around amesh network control system. Every node is capable of transmitting andreceiving commands or information. Each node is built around a similarRF platform for communication, with specific peripheral function addedfor specific node roles. Micro-current technologies allow for a platformwith a simple peripheral layout to last for years on a small form factorcoin-cell battery. With this realized, a printed circuit board and powersource can be built into the bottom-bar of a window covering, and theprinted circuit board can include many option peripheral add-on featuresand capabilities to operate the window covering in association withprinted circuit board 162.

An operating and control device can be integrated into the bottom rail,or an independent control unit can be docked to the bottom rail. Awindow covering can include a control system similar to a RF operatedremote control. This control system will allow the user to operate theshade locally, and include functions such as, for example, capacitivetouch control, user “bump” gesture control, object in path detection,auto-programming modes and the like. A user control system may be builtdirectly into the bottom rail, a so-called “smart rail”, or it may be anindependent unit such as operating and hand held remote control 152 thatcan be docked to and detached from the bottom rail, allowing remote use.The remote control user input device can operate when docked to thebottom rail, or when and held or resting away from the docking location.While the docking location can be on the shade itself, typically in thebottom rail, the docking location also can be a holder located at someother location, such as on the window frame or wall adjacent the shade,such as shown in FIG. 1.

As the window covering travels to its directed position, a controlsystem monitors data from various sources (accelerometer, I.R.detection, sonic feedback, etc.) to decide whether a foreign objectexists in the intended path of travel. This system will stop the shadeat or prior to the object, thereby protecting the shade from damage andthe object from harm. Various methods of object detection can be used.For example, a three axis accelerometer measuring physical movement canbe paired with an infrared emitter/detector combination that measuresobjects at a distance exceeding five inches.

When a portable, hand-held controller is provided, such as hand heldremote control 152, the window covering can be placed in a programmingmode, and “taught” to stop when the bottom rail is at the same elevationas the controller. This simple adjustment method enables the user tosimply activate the programming mode and then hold the controller at thedesired level for opening or closing the window covering, whereby thecontrol system learns to stop at that position. Thereafter, unlessreprogrammed, this will remain the limit of travel. It should beunderstood that a series of stop positions rather than a single stopposition also can be established in this way.

By utilizing ultrasonic sound waves, the position of the bottom rail inrelation to any obstacle beneath it, including the window sill, as wellas in relation to the headrail above it can be determined. The distanceis transmitted to the window covering lift system printed circuit board162 via RF signal. The distance is measured by transmitting a specificsound frequency, at a specific power, receiving the signal rebound, andmeasuring the time lapse. The calculated position can be used to providenumerous functions.

The ultrasonic positioning system can provide a method of locating thelower limit of travel by determining the distance to the first objectsensed. The detection cone is determined via software. The angle ofdetection and sound intensity may be tuned for individual situations. Inthis mode, the window covering will function properly without any priorconfiguration by the user if the window covering is preconfigured tocease travel a specified distance from the first object detected, whichcan be a window sill if no intermediate object is present. Withoutprogramming by the user, the window covering will stop automatically atthe predetermined distance from the window sill.

When the window covering receives a command to ‘travel’, a second RFsignal triggers the bottom rail system to wake up and begin transmittingsensor output. If a condition is met where an obstacle is detected inthe path of travel, the window covering will respond with an appropriateresponse, such as terminating movement. The bottom rail will end travelwhen the bottom rail approaches a specified minimum distance from theobject. This distance may be adjusted by the user to control how closethe bottom rail will travel to the object or window sill. Thisadjustment may be provided in the form of a small adjusting screw hiddenin the bottom rail. Alternatively, adjustment can be an electronicadjustment of the distance.

The use of ultrasonic sensing allows for different window covering mountconfigurations. The sensors detect anything inside a configurabledetection cone. The angle and intensity of the cone may be adjusted toallow for different detection models. When a window covering is mountedas an inside mount, the ultrasonic sound wave is directed verticallybelow the bottom rail, so as to detect the window sill below, or anyforeign object in the path of travel, such as, for example, a windowcrank.

When the window covering is mounted in an outside mount configuration,the ultrasonic sensor is still directed vertically beneath the bottomrail. However, adjustment of the cone angle allows for detection behindthe window covering. As the bottom rail approaches the sill below, thedetection cone will begin to see the sill behind the window covering.The larger the detection cone, the greater the distance can be betweenthe bottom rail and the window sill behind when detection occurs. Thedistance is a function of the cone angle. At a detection angle of30-degrees, the sensor can detect the window sill 2.5″ inches (about 6.4cm) behind the bottom rail when the bottom rail is at 10 inches (25.4cm) vertically from the sill.

Other design options for distance measurement also can be used. Byutilizing infrared emitting diodes and IR receptors, the detection of anobject in the path of travel may also be realized. When the IR receiverdetects reflected light of a specific wavelength, an object has beendetected, and the controls may respond with the appropriate command.

The use of infrared, ultrasonic or other position detection systemsprovide protection against product failure. When a motorized windowcovering encounters an obstacle in its normal path of travel, andcontinues its motion, product failure is likely to occur due toover-spooling of the lift cord. The design disclosed herein utilizes adetection system, such as ultrasonic detection or IR detection toeliminate this concern. During travel, if the window covering encountersan unexpected obstacle within the normal path of travel, the windowcovering will cease travel until the object is removed and the windowcovering can continue as normal. This will reduce over-spooling, whichin turn will decrease product returns, thus increase overall customersatisfaction.

An exemplary arrangement is shown in FIG. 4, wherein a window covering500 having a bottom rail 502 and window covering material 504 is shown.A transceiver 506 is included in a printed circuit board in bottom rail502 along with sensors and devices to provide added functions. Duringinitial command to travel, a signal is sent from a motor controltransceiver on printed circuit board 162 to the bottom rail slavetransceiver to wake up and initialize onboard sensors. Multiple sensoroptions can be built into the system. For example, an IR or sonicemitter/detector 506 can be included in bottom rail 502, and can be usedto detect the position of the bottom rail relative to a window sill 508,and/or to detect objects in the path of the window covering as it isbeing lowered, so as to avoid contact with the object by stopping travelof bottom rail 502 before damage can occur to window covering 500 or anyobject in the path of travel

A bottom rail sensing board also can be configured with a multi-axisaccelerometer IC. This sensor measures rate of displacement from a fixedhome position. When activated by the master motor control transceiver,this system measures the angle at which the bottom rail is sitting inrelation to the earth below. The tilt measurement provides conditionsfor multiple user functions by pushing, pulling, lifting or pressing therail to a different relative position. However, the multi-axisaccelerometer also can provide an additional safety factor againstdamage.

As shown in FIG. 42, a window covering 600 has a bottom rail 602 andwindow covering material 604. An accelerometer 606 is included in aprinted circuit board in bottom rail 602. A user 608 can manually alterthe position of bottom rail 602, such as by pushing to generate a signalfor lowering the window covering or slight lifting to instigate raisingthe window covering. Movement can continue until a pre-designated nextstop position is reached, or until another manual disruption is applied.Alternatively, operation can be in predetermined increments, with theuser instigating a sufficient number of taps or disruptions for thedesired number of incremental movements to reach the desired finalposition. For safety purposes, if the window covering encounters aforeign object in the normal path of travel, which was not detected bythe ultrasonic, IR or other sensors, the object will modify the normalpath of travel followed by the window covering. The change in travelpath, or tilt, will be detected by the accelerometer, and protectiveaction can be taken. In such conditions, a signal can sent to the masterprinted circuit board 162 with instructions to cease all movement; ceasedownward movement, reverse direction and travel to the upper limit; orcease downward movement, reverse direction and travel until tilt is nolonger detected. In this way, the window covering also can be made to beself-leveling.

The use of an accelerometer can distinguish between an object in thepath of travel, and a specific method of contact from the user. Forexample, if a certain sequence of ‘taps’ is detected, the windowcovering will respond with the associated command. For example, twoconsecutive taps can be used to command the window covering to stopmotion, another two tap to command the window covering to changedirections and travel to the associated limit. Such input also can beused for programming upper and lower travel limits for standardoperation of the window covering.

A bottom rail printed circuit board can be configured also with amagnetic positioning system. By utilizing magnets positioned on thewindow sill, molding, adjacent wall etc, an infinite number of‘intermediate’ stop positions can be realized. Multiple window coveringsmay be generically synchronized to stop at the same positions by placingthe required number of magnets at the desired stop positions. Theprinted circuit board located within the bottom rail can include asensor that detects certain levels of magnetic flux. A condition isdetermined according to the amplitude of the magnetic field imparted onthe sensor. The sensor can consist of magnetic reed switches, hallsensors, or a combination of both. The sensitivity of the sensor may beadjusted to account for various mount configurations and sensorpositions. Small form factor dense field magnets will be supplied to thecustomer to attach to the window, as needed. The magnets may be removedor adjusted without damage to the window sill.

A motion sensing IC is capable of sensing and responding to specificgesture movements made by the user. The bottom rail can utilize thistechnology. Sensing windows can be included into the bottom rail.Gestures made in view of these windows can be processed and compared topre-determined learned commands, allowing a user to control the windowcovering within a determined field, by simple bodily gestures withoutphysical contact with the window covering itself Ability to distinguishbetween specific gestures allows the user to provide a different gesturefor each specific command. A gesture sensing module may also be utilizedin a local wall mount controller (wall switch) instead of the bottomrail. For example, upward gestures, downward gestures, circular gesturesor the like can be used as commands to the system to perform certainactions.

A capacitive touch control unit built into the bottom rail printedcircuit board allows for user interface on the window covering itself.Multiple capacitive sense pads placed on the front and bottom of thebottom rail will provide the user with complete control of the windowcovering without the need for an RF link. The nature of capacitive touchcontrols is such that the components required can be concealed within anacceptable aesthetic design for the window covering. For example, thecapacitive touch control unit can be provided in a readily accessiblelocation of the bottom rail or bottom rail of the window covering, suchas along the bottom at one end of the bottom rail, FIG. 43 shows awindow covering 700 having a bottom rail 702 and window coveringmaterial 704. A capacitive touch sensing pad 706 is provided in bottomrail 702.

Handheld remote control user input device 152 can be a simple, intuitiveone-one radio frequency control unit. The radio control (“RC”) utilizesa minimal button design, having only what buttons are needed to operatea single local window covering. The RC can be linked to the host windowcovering during the manufacturing process, thus eliminating the need forany confusing linking steps to be performed by the consumer. The systemcan incorporate many options which may be built in or scaled back asnecessary for the scope of the product. The basic system includes asmall form factor, two button, tactile based design, with minimal userfunction, such as simple up/down movement commands with minimal light oraudible window covering feedback.

An improved design for the user input device can include a small dualstack motherboard/daughterboard capacitive or resistive touch design.The system will operate for three or more years on a 20 mm lion coincell, even without the previously described photovoltaic rechargingsystem. While the exemplary embodiment shown includes two operatingbuttons, it should be understood that a simple, one button device alsocan be used wherein successive activations of the single button switchcauses the motorized lift assembly 120 to start and stop operation on analternating basis.

Many of the features described above for using in a bottom rail also canbe included in improved versions of the handheld remote control userinput device. An accelerometer and/or infrared and/or capacitive touchcontrol system embedded into the bottom rail system detailed above alsocan be utilized in the remote control user input device to allow for thesame operation of the functions detailed above. This system also willallow the user to ‘dock’ or simply clip the remote control user inputdevice to the bottom rail of the window covering, and configure it in aspecified mode to allow for local user function and window coveringpositioning. This will allow the remote control user input device tobecome different types of controls, depending on which mode is enabledon the remote control user input device. For examples and notlimitation, through appropriate activation the user input device canbecome any of the following types of controls, as described previously;a physical bump user gesture control using an accelerometer, acontactless gesture control with a motion sensing IC, a foreign objectdetection system using IR or sonic sensors and/or an accelerometer,and/or an automated and self-programming window size fitting unit usingthe IR and/or sonic sensors.

The infrared detector/emitter combination mounted so that it is windowedthrough the housing will allow for incoming hand detection fromapproximately five inches away. This detection mode is available withthe remaining system in a sleep mode, with 7 uA current draw. This willallow the remote control user input device system to wake and givefeedback (light language) to the user before actually contacting thecontrol source. This feature will also serve several purposes in that itmay be mounted or generically fastened to the bottom surface of thewindow covering bottom rail, allowing for the self-programming featurediscussed above.

The system can provide multiple RF remote control options. One option inparticular is specified as a small form remote that can be easilyadhered to the window sill or molding. This small form factor remoteserves as a local RF control station for the window covering, and in amultiple window installation a separate small form remote can beprovided for each individual window covering. If mounted on or near thewindow covering that it operates, it effectively substitutes for aconventional operating cord to operate one and only one window covering.A simple interface will provide the user with controls for (and notlimited to) all motion. The small form remote also may serve as adocking station for the handheld remote control.

The remote control user input device may be implemented as a passivemounting dock for a multi-window covering remote. The bottom rail mayinclude a socket or dock to allow the remote control user input deviceto be placed and held in it, as shown in FIG. 44. A window covering 800includes a bottom rail 802 and window covering material 804. A receiveror socket 806 in bottom rail 802 is configured to receive and retain aremote control user input device 808. With the controls facing out onremote control user input device 808, operation of the remote controluser input device can continue even while it is docked in the bottomrail.

Still other variations and uses are possible. Common motorized controlsare found in the headrails of window coverings. With the systemsdisclosed herein, which are both lightweight and compact, the drive andcontrol mechanisms can be located in the bottom rail of the windowcovering. In such a system, the lift cords are fixed at the upper end inthe headrail, and winding mechanisms are provided in the bottom rail to“walk up” the lift cord by winding from the bottom when raising thewindow covering.

Photovoltaic cells can be provided on the bottom rail or other locationsto power a battery charging system. The system described herein requiresvery little current to operate in ‘stand-by’ mode, as little as 4 uA.This allows the system to operate for several years on a standard coincell. However, film technology solar cells may be implemented toeliminate the need for batteries. The combination of micro-currentconsuming sleep modes, short operating duty cycles, and specific batterydesign allow the entire automated window covering system to be poweredindefinitely by means of solar power. Film style solar panels can beused in the design of the fixture to provide operational current whennecessary, and to supply a battery charging circuit when in standby forthe mechanical life of the window covering. Ambient room lightingcoupled with intermittent solar radiation can provide the needed currentto operate the system, including any operating and control device andthe window covering motor

The control system for the window covering may be linked with a homepersonal computer, allowing window covering status data to be sent viainternet. This information can be used to assist a customer service teamin troubleshooting the product in the field. Linking to a smartphone orother portable unit can allow a home owner to monitor or controloperation from distant locations.

To avoid complexity for the end-user, the window covering system canemploy an automated method for configuring the window covering to fitthe opening it is mounted in or on. This system can use a method ofdetection similar to that described above for object detection.Alternatively or conjunctively, the “Remote control user input device”control unit can be used as a virtual marker placed at the desired limitof movement, so that programming will establish that limit as the stoppoint for raising or lowering the window covering.

Variations and modifications of the foregoing are within the scope ofthe present invention. It is understood that the invention disclosed anddefined herein extends to all alternative combinations of two or more ofthe individual features mentioned or evident from the text and/ordrawings. All of these different combinations constitute variousalternative aspects of the present invention. The embodiments describedherein explain the best modes known for practicing the invention andwill enable others skilled in the art to utilize the invention. Theclaims are to be construed to include alternative embodiments to theextent permitted by the prior art.

Various features of the invention are set forth in the following claims.

1. A motorized lift assembly for a window covering having movable windowcovering material and cords for moving the window covering material,said motorized lift assembly comprising: a motor assembly including amotor; a gear train driven by said motor for adjusting positions of saidcords; and an operating and control device mounted to a portion of saidwindow covering for operating the motor in response to user input. 2.The motorized lift assembly of claim 1, said operating and controldevice including an accelerometer responsive to movement of saidoperating and control device.
 3. The motorized lift assembly of claim 1,including a gesture recognition feature responsive to gestures by theuser.
 4. The motorized lift assembly of claim 1, including a positionrecognizing sensor for determining a position of the window coveringmaterial relative to objects nearby.
 5. The motorized lift assembly ofclaim 1, the window covering including a bottom rail and anaccelerometer in the bottom rail.
 6. The motorized lift assembly ofclaim 1, the window covering including a bottom rail and a gesturerecognition feature in the bottom rail responsive to gestures by a user.7. The motorized lift assembly of claim 1, the window covering includinga bottom rail and a position recognizing sensor that determine aposition of the bottom rail relative to objects below the bottom rail.8. The motorized lift assembly of claim 1, including a motor controlcircuit board in two-way communication with said operating and controldevice.
 9. The motorized lift assembly of claim 1, the window coveringincluding a bottom rail with a receiver for holding and releasing saidoperating and control device.
 10. The motorized lift assembly of claim1, said operating and control device including a hand-held remotecontrol and a remote control mounting device.
 11. The motorized liftassembly of claim 1, said operating and control device having acapacitive touch sensor.
 12. A motorized lift assembly control devicefor operating a window covering having a motor, movable window coveringmaterial and cords for moving the window covering material; saidmotorized lift assembly control device comprising: a user activatablecontrol; a communication component in said user activatable control foroperating the motor; and a holder for said user activatable control on aportion of the window covering.
 13. The motorized lift assembly controldevice of claim 12, including two-way communication between said useractivatable control and a printed circuit board controlling the motor.14. The motorized lift assembly control device of claim 12, including anaccelerometer.
 15. The motorized lift assembly control device of claim12, including a gesture recognition feature responsive to gestures bythe user.
 16. The motorized lift assembly control device of claim 12,including position recognizing sensors for determining a position of thewindow covering material relative to objects nearby.
 17. The motorizedlift assembly control device of claim 12, the window covering includinga bottom rail; and said user activatable control in said bottom rail.18. The motorized lift assembly control device of claim 17, saidactivatable control being attachable to and detachable from the exteriorof the bottom rail.
 19. The motorized lift assembly control device ofclaim 12, including a sonic emitter/detector.
 20. The motorized liftassembly control device of claim 12, including an infraredemitter/detector.